From 8446f1d391f3d27e6bf9c43d4cbcdac0ca720417 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Tue, 6 Sep 2005 15:16:27 -0700 Subject: [PATCH] detect soft lockups This patch adds a new kernel debug feature: CONFIG_DETECT_SOFTLOCKUP. When enabled then per-CPU watchdog threads are started, which try to run once per second. If they get delayed for more than 10 seconds then a callback from the timer interrupt detects this condition and prints out a warning message and a stack dump (once per lockup incident). The feature is otherwise non-intrusive, it doesnt try to unlock the box in any way, it only gets the debug info out, automatically, and on all CPUs affected by the lockup. Signed-off-by: Ingo Molnar Signed-off-by: Nishanth Aravamudan Signed-Off-By: Matthias Urlichs Signed-off-by: Richard Purdie Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/sched.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'include/linux') diff --git a/include/linux/sched.h b/include/linux/sched.h index dec5827c774..5fb31bede10 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -176,6 +176,23 @@ extern void trap_init(void); extern void update_process_times(int user); extern void scheduler_tick(void); +#ifdef CONFIG_DETECT_SOFTLOCKUP +extern void softlockup_tick(struct pt_regs *regs); +extern void spawn_softlockup_task(void); +extern void touch_softlockup_watchdog(void); +#else +static inline void softlockup_tick(struct pt_regs *regs) +{ +} +static inline void spawn_softlockup_task(void) +{ +} +static inline void touch_softlockup_watchdog(void) +{ +} +#endif + + /* Attach to any functions which should be ignored in wchan output. */ #define __sched __attribute__((__section__(".sched.text"))) /* Is this address in the __sched functions? */ -- cgit v1.2.3